Process for the preparation of vinyl derivatives



Patented Sept. 20, 1938 UNITED STATES 2,130,451 PATENT QOFFIC'E' PROCESSFOR THE PREPARATION VINYL DERIVATIVES Georges E. Zelger,

Montrenil-sous-Bois, Seine,

France, assignor, by mesneassignments, to Eastman Kodak Company, JerseyCity, N. 1., a corporation of New Jersey No Drawing. Application May16,1935, Serial No. 21,878. In France May 23, 1934 16 Claims.

This application is a continuation-in-part of my copending applicationSerial No. 706,099, filed January 10, 1934.

Condensation products of a polyvinyl alcohol and an aldehyde obtainedaccording to known processes have various disadvantages. For example,certain of these condensation products are insoluble in all solvents,while others are soluble, but give rise to solutions of relatively lowviscosity. Such solutions of lower viscosity are unsatisfactory for manypurposes. in the manufacture of films, filaments, threads and the likefrom these condensation products, to

employ condensation products which are entirelysoluble in suitablesolvents and in addition give solutions of high viscosity with thesesolvents.

Now, I have found that condensation products of a polyvinyl alcohol andan aldehyde which give solutions of high, practically maximum viscositywith suitable organic solvents, such as a mixture of four volumes ofmethylene chloride and one volume of pure ethyl alcohol, ethylenechloride, tetrachlorethane chloroform or other suitable organicsolvents, preferably mixed with a small amount of alcohol, can beprepared by effecting the condensation in the presence of an amount ofcatalyst slightly in excess of that amount necessary to produce acondensation product just insoluble in the suitable organic solvent,previously selected. I have also found that this amount of catalyst canbe varied only within narrow limits, 40 if the resulting condensationproduct is to form solutions of high, practically maximum viscosity.

The object of this invention, therefore, is to provide condensationproducts of a polyvinyl alcohol and an aldehyde which give solutions ofhigh, practically maximum viscosity with suitable or'- ganic solvents. Afurther object is to provide a process for the preparation of such vinylcondensation products. Other objects will appear hereinafter.

According to my invention, the maximum amount of catalyst, which gives acondensation product just insoluble in the chosen organic solvent, isdetermined by trial condensations, using progressively larger amounts ofcatalyst. Then for the desired condensation product, an amount ofcatalyst just slightly in excess of that amount previously determined isemployed. If the catalyst is hydrogen chloride and if the condensationis efiected at ordinary temperatures, that is, about C., the excess ofcatalyst is equal to less than In fact, it is essential,

1% of the weight of the total reaction mass. (See Example 1.)

It has proven more satisfactory to approach the transition point,solubility-insolubility, from the insoluble side. As the amount ofcatalyst is increased for the successive trial condensations, thecondensation products become softer and softer when in contact with thesolvent and tend to disperse more and more therein, until finally aproduct is obtained which appears to give a homogeneous dispersion inthe solvent. Close examination reveals, however, that this mixture isnot homogeneous but rather is made up of small swollen particles of thecondensation product dispersed throughout the solvent. If now, theamount of catalyst is but slightly increased for the next condensation,a product is obtained which is entirely soluble and the resultingsolution is. ofa high, practically maximum viscosity. Larger amounts ofcatalyst give rise to condensation products which form solutions ofdefinitely lower viscosity. If the catalyst employed is hydrogenchloride, I have found the excess to be employed in the finalcondensation 0.3% and about 1% of the weight of the total re-. actionmass. g

The following examples serve to illustrate my invention, but are notintended to be limiting. In these examples, the polyvinyl alcohols aredefined by indicating the Engler viscosity of their 4% aqueous solutionsat 15 C. and the concentration of catalyst is expressed as a percent ofthe weight of the total reaction mass. (See Example 1.)

Example 1.-100 g. of a polyvinyl alcohol (Engler viscosity 63) weredissolved in 1 liter of water,

to vary between about grams of trioxymethylene were added and to the theacid was hydrogen chloride, 132g. of hydro-' genchloride had beenintroduced. Thus the amount of hydrogen chloride (132 g.) was equal to8.8% of the total reacting mass (1492 g.). The mixture was stirred orotherwise agitated and allowed to react at about 20 C. At the end offrom one to two hours, the trioxymethylene went into solution, giving atransparent liquid. At the end of several hours a white compact mass ofthe vinyl condensation product'precipitated. This product was washed anddried. It was completely soluble in a mixture of four volumes ofmethylene chloride and one volume of pure ethyl a1- cohol, a 2% solutionhaving an Engler viscosity of 61 at.14 C.

With a concentration of hydrogen chloride equal to 10% of the totalreacting mass, the vinyl condensation product gives a solution in amixture of four volumes of methylene chloride and one volume of pureethyl alcohol which is very gler viscosity 63) were treated At highertemperatures,

fluid and of lower viscosity. With a concentration of 8%, the product isincompletely soluble, giving a gel which is notv homogeneous.

Example 2.-100"g 0f polyvinyl alcohol (Engler viscosity 97) were treatedas in Example 1, but in the presence of 12% hydrogen chloride. The vinylcondensation produchgave a 2% solution in a mixture of four volumes ofmethylene chloride and one volume of pure ethyl alcohol having an Englerviscosity of 65 at 15 C., such a viscosity being the maximum obtainedwith a polyvinyl alcohol of this degree of polymerization.

With a concentration of hydrogen chloride equal to 11% of the totalreacting mass, the vinyl condensation product was quite insoluble in amixture of four volumes of methylene chloride and one volume of pureethyl alcohol. f

Example 3.100 g. of a polyvinyl alcohol (Engler viscosity 38) weretreated as in Example 1, but in the presence of 7% hydrogen chloride.The vinyl condensation product gave a 2% solution in a mixture offour-volumes of methylene chloride and one volume of pure ethyl alcoholhaving an Engler viscosity of 30 at 15 C., such a viscosity being themaximum obtained with a polyvinyl alcohol of this degree ofpolymerization.

With a concentration of hydrogen chloride equal to 6.7% of the totalreacting mass, the vinyl condensation product was insoluble in a mixtureof four volumes of methylene chloride and one volume of pure ethylalcohol, giving rise to swollen particles which dispersed but did notdissolve to give a solution.

Example 4.100 g. of a polyvinyl alcohol (Enas in Example '1, but at atemperature of to 80 C., and in the presence of 15.5% hydrogen chloride.The vinyl condensation product gave a 2% solution in a mixture of fourvolumes of methylene chloride and one volume of pure ethyl alcoholhaving an Engler viscosity of 48 at 15 C.

With a concentration of hydrogen chloride equal to 12.5% of the totalreacting mass, the vinyl condensation product is incompletely sol-.

uble in a mixture of four volumes oi methylene chloride and one volumeof pure ethyl alcohol. 1

Example 5.100 g. of a polyvinyl alcohol (Engler viscosity 63) weretreated as in Example 1, but in the presence of 25% fate. The vinylcondensation product gave a 2% solution in a mixture 01' four volumes ofmethylene chloride and one volume of pure ethyl alcohol having an Englerviscosity of 45 at 15 C.

With a concentration of hydrogen sulfate equal to 23.5% of the totalreacting mass, the vinyl condensation product is incompletely soluble ina mixture of four volumes of methylene chloride and one volume of pureethyl alcohol.

From these examples it can be seen that the absolute amount of hydrogenchloride necessary to produce a condensation product of a polyvinylalcohol and an aldehyde which gives a solution of high practicallymaximum viscosity with a mixture of four volumes of methylene chlorideand one volume of pure ethyl alcohol varies between about 7% and 12% 01'the .weight of the total reaction mass, depending upon the particularpolyvinyl alcohol 'employed and when the condensation is effected atordinary temperatures. that is from about 60 C. to about 80 C., theabsolute'amount of hydrogen chloride is somewhat higher varying fromabout 14% to about 20%.

From these examples, it can also be seen that the amount of catalystnecessary to produce a of hydrogen sul-" condensation product of aparticular polyvinyl .alcohol and an aldehyde which dissolved completelyin a suitable, previously selected organic solvent and gives therewith asolution' of high practically maximum viscosity is Just slightly inexcess of that necessary to produce a condensation product justinsoluble in the previously selected organic solvent. Further, it can beseen that the absolute amount of catalyst which gives rise to thedesirable condensation product can be varied within but narrow limits.

It is to be noted that my invention is not limited to the aboveexamples, nor to the choice 01' the bodies employed, nor to catalysts,the proportions indicated for catalysts falling according to the bodiesemployed and according to the nature of the catalysts. At ordinarytemperatures 1. e. about 20 C. where A% represents the amount ofhydrogen chloride, based on the weight of the total reacting mass,necessary to produce a condensation product of a polyvinyl alcohol andan aldehyde just insoluble in a previously selected organic solvent,from about (A+0.3) to about (A+1.0)% of hydrogen chloride, based on theweight of the total reacting mass, produces a condensation product of apolyvinyl alcohol and an aldehyde which gives a solution of high,practically maximum viscosity in the previously selected organicsolvent.

In the claims, the polyvinyl alcohols are defined by indicating theEngler viscosities of their 4% aqueous solutions at 15 C. and theamounts of catalyst are indicated as a percent of the weight of thetotal reaction mass. (See Example 1.) The term aldehyde is intended tomean 1 an aldehyde in either its monomeric or its polymeric form e. g.formaldehyde is intended to mean either monomeric formaldehyde or one01' its polymers such as trioxymethylene.

What I claim as my invention and desire to be secured by 'Letters Patentof the United States is:

1..A process for the preparation of a condensation product of apolyvinyl alcohol and an aldehyde which gives a solution of highviscosity in a previously selected organic solvent comprising condensinga polyvinyl alcohol with an aldehyde, in the presence of about (A+0.3)percent to about (Ii-+1) per cent by weight of a catalyst, based on thetotal weight of the reac-- tion mass, where A percent represents theamount of catalyst necessary to produce a condensation productjustinsoluble in the previously selected organic solvent.

2. A process for the preparation of a condensation product of apolyvinyl alcohol and formaldehyde which gives a solution of highviscosity in a previously selected organic solvent comprising condensinga polyvinyl alcohol with formaldehyde, in the presence of about (A+0.3)percent to about (A+1) percent by weight of a catalyst, based on thetotal weight of the reaction mass, where A. per cent represents theamount of catalyst necessary to produce a condensation product justinsoluble in the previously selected organic solvent.

3. A process for the preparation of a condensa tion product of apolyvinyl alcohol and an aidehyde which gives a solution of highviscosity in a previously selected organic solvent comprising condensinga polyvinyl alcohol with an aldehyde, in the presence of about (A+0.3)percent to about (A+1) percent by weight of acid catalyst, based on thetotal weight of the reaction mass, where A percent represents the amountof acid catalyst necessary to produce a condensation product justinsoluble organic solvent.

4. A process for the preparation of a condensation product of apolyvinyl alcohol and formaldehyde which gives a solution of highviscosity in a previously selected organic solvent comprising condensinga polyvinyl alcohol with formaldehyde, inthe presence of about (A+0.3)percent to about (A+1) percent by weight of acid catalyst, based on thetotal weight of the reaction mass, where A percent represents the amountof acid catalyst necessary to produce a condensation product justinsoluble in the previously selected organic solvent.

5. A process for the preparation of a condensation product of apolyvinyl alcohol and an aldehyde which gives a solution of highviscosity in a previously selected organic solvent comprising condensinga polyvinyl alcohol with an aldehyde, in the presence of from about(A+0.3) percent to about (A+1) percent by weight of hydrogen chloride,based on the total weight of the reaction mass, where A percentrepresents the amount of hydrogen chloride necessary to produce acondensation product just insoluble in the previously selected organicsolvent.

6. A process for the preparation of a condensation product of apolyvinyl alcohol and formaldehyde which gives a solution of highviscosity in a previously selected organic solvent comprising condensinga polyvinyl alcohol with formaldehyde, in the presence of from about(AA-0.3) percent to about (A-i-l) percent by weight of hydrogenchloride, based on the totalweight of the reaction mass, where A percentrepresents the amount of hydrogen chloride necessary to produce acondensation product just insoluble in the previously selected organicsolvent.

'7. A process for the preparation of a condensation product of apolyvinyl alcohol and an aidehyde which gives a solution of highviscosity in a mixture of about four volumes of methylene chloride andabout one volume of ethyl alcohol comprising condensing a polyvinylalcohol with an aldehyde, in the presence of from about (Ag-0.3) percent to about (A+l) per cent by weight of hydrogen chloride, based onthe total weight of the reaction mass, where A per cent represents theamount of hydrogen chloride necessary to produce a condensation productjust insoluble in the mixture of chloride and about one volume of ethylalcohol.

8. A process for the preparation of a condensationproduct of a polyvinylalcohol and an aldehyde which gives a solution of high viscosity in amixture of about four volumes of methylene chloride and about one volumeof ethyl alcohol comprising condensing a polyvinyl alcohol withformaldehyde, in the presence of from about A+0.3) per cent to about(AH-1) per cent by weight of hydrogen chloride, based on the totalweight of the reaction mass, where A per cent represents the amount ofhydrogen chloride necessary to produce a condensation product justinsoluble in the mixture of about four volumes of methylene chloride andabout one volume of ethyl alcohol.

9. A process for the preparation of a condensation product of apolyvinyl alcohol and an aidehyde which gives a solution of highviscosity in a {mixture of about four volumes of methylene chloride andabout one volume of ethyl alcohol comprising condensing, at about 20 0.,a polyvinyl alcohol with an aldehyde, in the presence of-Irom in thepreviously selected.

about four volumes of methylene weight or the reaction mixture,

about (A+0.3) per cent to about (A+l) per cent by weight of hydrogenchloride, based on the methylene chloride and about one volume of ethylalcohol.

10. A process for the preparation of a condensation product of apolyvinyl alcohol and an aldehyde which gives a solution of highviscosity in a mixture of about four volumes of methylene chloride andabout one volume of ethyl alcohol comprising condensing, at about 20 C.,a polyvinyl alcohol with formaldehyde in the presence'of from about(A+0.3) per cent to about (A+1) per cent by weight of hydrogen chloride,based on the total weight of the reaction mass, where A per centrepresents the amount of hydrogen chloride necessary to produceacondensation product just insoluble in the mixture of about fourvolumes of methylene chloride and about one volume of ethyl alcohol. I

11. A process for the preparation of a condensation product of apolyvinyl alcohol and an aldehyde comprisin condensing a polyvinyl al-.cohol of Engler viscosity about 38 with an aldehyde, in the presence ofabout 7 per cent by weight of hydrogen chloride,'based on the weight ofthe total reaction mass, at about 20 C.

12. A process for the preparation of a condensation product of apolyvinyl alcohol and formaldehyde comprising condensing a polyvinylalcohol of Engler viscosity about 38 with formaldehyde, in the presenceof about '7 per cent by weight of hydrogen chloride, based on the totalweight of the reaction mass, at about 20 C.

13. A process for the preparation of acondensation product of apolyvinyl alcohol and an aldehyde comprising condensing a polyvinylalcohol of Engler viscosity of about63 with an aldehyde, in the presenceof about 8.8 per cent by weight of hydrogen chloride, based on the totalweight of the reaction mass, at a temperature of about 20 C., and in thepresence or about 15.5 per cent by weight of hydrogen chloride, based onthe total weight of the reaction mixture at from about 60 C. to about C.

aldehyde, in the presence of about 8.8 per cent by,

weight of hydrogen chloride, based on the total weight of the reactionmass, at a temperature or about 20 C. and in the presence of about 15.5per cent by weight of hydrogen chloride, based on the total weight ofthe reaction mixture, at from about 60 C. to about 80 C.

15. A process for the preparation of a condensation product of apolyvinyl alcohol and an aldehyde comprising condensing a p yv nylalcohol of Engler viscosity of about 9'7 with an al.- dehyde, in thepresence of about 12 per cent by weight of hydrogen chloride, based onthe total weight of the reaction mass, at about 20 C.

16. A process for the preparation of a condensation product of apolyvinyl alcohol and formaldehyde comprising condensing a polyvinylalcohol of Engler viscosity about 97 with formaldehyde, in the presenceof about 12 per cent by weight of hydrogen chloride, based on the totalGEGRGES E. znmm.

at about 20 C.

